QCad/C2/Drawing-Methods-in-QCAD/English-timed

Time	Narration
00:00	Hello and welcome back to another QCAD tutorial
00:04	Drawing methods in QCAD and knowing coordinate system.
00:09	QCAD uses Cartesian co-ordinate system which consists of two numbered scales, called as x-axis, y-axis.
00:17	These are perpendicular to each other. These axes divide coordinate system into 4 quadrants.
00:24	Your work in QCAD will mostly be in quadrant I.
00:27	The point where these axes meet is called as absolute origin or the origin point.
00:34	For this tutorial, I am using the GNU Linux operating system Ubuntu Version 10.04 LTS
00:40	and QCAD Community Edition Version 2.0.5.0
00:46	In this tutorial, we will see:
00:48	Cartesian coordinate system
00:51	How to use command line to draw objects and
00:53	different drawing methods available in QCAD.
00:56	Let's first see how to use command line to put in co-ordinates, to draw points and draw objects of required measurements
01:06	using the Cartesian coordinate system.
01:08	Please have the QCAD application open in your system.
01:11	If you want to know how to install QCAD, please refer to the earlier tutorial called 'Introduction to QCAD'
01:18	which is available on spoken-tutorial website.
01:22	Once the application is open, from the tool bar on left, choose Line tool- Line with two points.
01:28	Now focus on the command prompt because we are going to use command line to put in exact coordinates.
01:35	It is asking to 'specify first point'. Let's put 10 comma 10.
01:41	We always put X-axis value first and then the Y-axis value.
01:45	What it is going to do is, it will add a point, 10 units away from X and from Y-axis.
01:53	Hit Enter. See the point is entered in relation to this origin or absolute 0, 0
02:00	which is 10 units away from X and 10 units away from Y-axis.
02:05	Now, suppose I want to draw a horizontal line in this direction, going away from this point, say 10 units.
02:13	For the next point, I will add 20, 10.
02:18	X-axis value is 20 because this point, the new point, will always be in relation to this absolute zero.
02:27	So, to meet the distance of 10, I will have to add 10 units to the earlier point's X-value.
02:35	And Y-value will not change; so, it will be 10 here.
02:40	Now, if I want to go vertical line downwards again of 10 units,
02:46	for the next point at the command prompt, I will put 20, 0.
02:56	X-axis value won't change, Y-axis will be 20 units -ve from the earlier value. So, it will be 0.
03:05	Now, again to go horizontal in 9 (nine) O'clock direction, for the next point, I will put (showing on application so pause for 4 sec. 3:11-3:15) 10, 0.
03:20	Here, Y-axis won't change and X-axis will be -10
03:26	in relation to the previously drawn point.
03:29	Now, to close my drawing I can always put 'c' and hit Enter or
03:35	I can go back to my original point which was 10, 10
03:39	and it will close the drawing. This is how you draw using the command line input.
03:45	You can draw any drawing by using this coordinate system by adding, subtracting absolute co-ordinates for any point or vertex between two segments
03:56	like I did to draw this 10 units.
04:00	But this is going to be little complicated.
04:03	Rather QCAD offers three easy methods to draw objects with.
04:09	First is Relative co-ordinates System.
04:12	It uses coordinates that are relative to the last point designated, rather than a 0,0 point of the drawing area.
04:19	"@" symbol is used to enter data, using this system.
04:26	Let's try drawing this previously drawn square, using relative coordinate system.
04:30	Let me clear my drawing.
04:35	Go back to line tool- Line with two points.
04:38	To specify first point, at the command prompt, enter 10,10- again X and Y-axis.
04:46	It is going to put point at 10,10 distance. For the next point, now that we are using relative system, we have to put '@' symbol.
04:57	Whenever we want to use relative system '@' symbol is a must.
05:01	After that, I want to draw horizontal line in 3 O'clock direction of 10 units.
05:08	So, X value is 10. So, I put @10,0 because Y value is zero here.
05:16	Now, for the vertical line going in downward direction, again for relative I use '@'.
05:24	Then X value is zero but Y becomes -10 because it is going in opposite direction. That is why value is -ve (negetive) here.
05:36	For the next horizontal line in 9 O'clock direction, I say @.
05:43	Now X-axis is -ve (negetive), it is going in opposite direction in relation to the previously drawn point -10,0.
05:53	And now, to close the drawing, I can put 'C' and Enter.
05:57	Or to go back to that original point- This case I say @ 0 X-axis is zero and Y is going vertical in +ve direction, so +10.
06:11	This is how you draw using relative coordinate method.
06:16	Next is Relative Polar co-ordinate system.
06:20	It relies on distance and angle relative to the last specified point.
06:24	Always it is positive and represents distance away from the first point.
06:30	Let's try and draw the previously drawn square, using this (relative) polar coordinate system.
06:36	In polar coordinates, right towards 3 O'clock is always default zero angle.
06:42	All other angles are calculated in anti-clockwise direction related to default zero.
06:48	So, let's go to Line tool – again Line with two points.
06:52	At the command prompt, specify first point as 10,10. Enter. Point is drawn.
07:00	Now, to draw horizontal line of 10 units using relative polar coordinates, I first put @ symbol because it is relative method.
07:10	Then I say distance, I know which is 10.
07:14	I use this symbol (<) less than symbol “<” for angle
07:23	I know angle is in 3 O'clock direction, which is zero. (@10<0)
07:28	So, my horizontal line of 10 units is drawn.
07:30	For the vertical line in downward direction, I again put @10<270
07:37	and 270 as angle this time because anti-clockwise downward is 270.
07:50	For the next point, horizontal line in 9 O'clock direction,
07:54	I say @10<180, angle will be 180 as it is exactly opposite to the default zero position.
08:05	Lastly, I can always put 'c' to close or else enter the point as @10<90; because, it is going in upward direction.
08:16	This completes our drawing in Polar coordinates method.
08:19	Third is the Direct distance method
08:22	which can be used to draw lines by specifying first point in relation to already drawn object using snapping tools
08:30	by placing a cursor at that point and entering a distance value.
08:35	Let's say- in this drawing, if I want to put a horizontal line going in 3 O'clock direction exactly from this point.
08:43	I can do so by using this direct method.
08:50	I choose Line- Line with two points. Now I know exactly at what point I want line ahead.
08:57	So, from Snapping options on the left tool bar, I choose 'snap to endpoint' and then go on that point and left-click to select the first point.
09:09	Now, in relation to this I want to draw horizontal line of 20 units.
09:15	So, I use command line to specify my next point.
09:20	I can use relative polar coordinate system here.
09:24	Since it is relative, I say @ now distance is 20 and in 3 O'clock direction which is default zero angle. So, I say @20<0
09:36	and Enter. The line is drawn.
09:39	Now say, I want vertical line of say 7 units going in 90 degrees direction.
09:46	I can use now relative co-ordinate method here.
09:52	And, say @ (I know 7 is Y direction and X is zero) so 0,7
10:01	and I can use relative coordinate method to draw this vertical line.
10:07	Again, if I want horizontal line going in 9 O'clock direction, say 5 units away.
10:12	I can again use relative coordinate method. At the command prompt, I say @ -5 now because X value will be negetive comma 0, Y is zero.
10:18	Now, I can close down this line because I know the distance is 7.
10:33	I can draw vertical line going towards 6 O'clock direction.
10:39	Once I know all the different methods I can draw objects with, I can use combination of any to draw objects.
10:46	So, now to draw that vertical line, I can use relative polar method.
10:51	So, I say @ I know distance is 7, I use '<' (angle) symbol since it is 6 O'clock direction, it is going to be 270.
11:00	This completes our drawing.
11:06	This is how you use different methods in QCAD.
11:10	Now that you are familiar with drawing methods and the coordinates system in QCAD,
11:15	Let's come to the assignment.
11:17	I would like you to draw diagram as shown in the figure.
11:20	You can either use relative coordinate, relative polar, direct method or combination of any method to draw this.
11:29	I would like to acknowledge the Spoken tutorial project which is part of the Talk to a teacher project.
11:33	It is supported by the National Mission on Education through ICT, MHRD, government of India.
11:40	For more information on this, please visit following website.
11:46	Thank you.Hope you are enjoying exploring QCAD.
11:50	This is Leena, signing off.

Contributors and Content Editors

Minal, Nancyvarkey, PoojaMoolya, Pratik kamble, Sandhya.np14